1. Field
Exemplary embodiments broadly relate to a method and a system for power control of an electrical device, and more particularly, to a method and a system for power control of an electrical device based on a control algorithm that controls the maximum power usage time.
2. Description of the Related Art
Smart grid is a next generation power network that combines IT technology with an existing power network and enables power providers and consumers to exchange two-way real-time information to maximize energy efficiency and to effectively manage power supply. The smart grid is being developed for a purpose of decreasing energy waste by increasing energy efficiency and for a purpose of achieving a greenhouse gas reduction effect by activating distributed power based on renewable energy to decrease energy dependency on fossil fuels.
When such smart grid is installed, electricity costs change in real time depending on power consumption and consumers control energy consumption according to the changing electricity costs. For example, the electricity costs are lower during late night hours when power consumption is low and is higher during daytime peak hours when people's activities cause greater power consumption. This may lead to customers, who for example, charge an electric car during the late night hours when the electricity costs are lower. Such a pattern of electricity consumption is reasonably managed by charging different rates differently according to a usage time.
In an approach to control power consumption by a power provider, a power providing system that receives power from the power provider and distributes the power to consumers is provided. This system may employ a peak power system to operate a maximum demand power control system in order to resolve instability of the power supply, and maximum demand power equipment that is used for the peak power period.
The maximum demand power equipment first determines a target peak power of a power consumer, predicts an estimated power demand in a period of 15 minutes through the increase trend of current power, and shuts down several circuit loads such that the estimated power demand does not exceed the peak power, thereby adjusting power consumption to be less than a target power.
Also, the maximum demand power controller has a built-in microprocessor installed therein such that a power load is always monitored, the estimated power demand is predicted for the period of 15 minutes, and several circuit loads are shut down for the estimated power demand not to exceed the peak power, thereby adjusting power consumption to be less than a target power.
Further, the maximum demand power controller has a built-in microprocessor installed therein such that the power load is always monitored, and when it is estimated that the power load will exceed a predefined target peak power within 15 minutes, an alarm is generated as well as power is shut down to unnecessary loads (preset loads) up to 8 loads in sequence to suppress the maximum demand power to be equal to or lower than the target power, and when the load is decreased, the loads are again introduced in sequence by a program set in advance. In other words, the maximum demand power controller controls to shut down power provided to the load such that power consumption may not exceed the target power, thereby maintaining the power consumption.
However, there is a problem in that the load that can be controlled by the maximum demand power controller is limited to, for example, an air conditioner, a refrigerator, or air conditioning equipment in a building. Moreover, a one-way control approach to control the peak power by simply cutting off power is inconvenient to the user.